Michael McGee wrote:
Doing some dreaming..
What do you guys think of the viability of a front cover cast into
the form
of a standard Lycoming dynafocal-1 mount?
A loose collection of my thoughts so far:
I think it would sell well enough to get the price under $500 for the
kit. I was bs-ing with the local rotary engine builder the other
day and
he showed me a very nice third-gen oil pan that was cast as a
replacement
for the stamped steel original. The reason behind the pan is
another story
but the casting work looked great (from this engineer/ non-casting
expert's
perspective anyway). He insists that he has a casting guy that is
capable
of making what we need if I can get him a proto type part.
The idea behind this is fairly sound since it would eliminate some of the
engineering rotary conversion folks go through. You need to control the
price
as much as possible to keep it attractive. Would this be an addition to a
traditional dynafocal mount that basically adapts the Mazda engine to
it, or a
dynafocal-like mount with multiple pieces, that could support either
engine?
Would your front plate be enough to mount the engine with, or would we
still
need to fabricate additional support members to the far side of the engine?
Brock's Lycoming mount for the Cozy is $625. If your item is an adapter
to a
dynafocal, it would cost me, as a builder, $1125 for this combination. The
Conversion Concepts mount (if you set aside Paul's issues with it for
the time
being) is $1098. That's not unattractive for a mount that does more (by
allowing the use of either engine, making the plane easier to sell, or
making
retrofits easier). However, if the cost climbed much above your
estimate or if
additional engineering was still required, it would be harder to compete.
With respect to the water pump, should I tease Paul and suggest an electric
water pump? =)
How serious are you about creating this? If you started and then
changed your
mind after making a few, would you publish the specifications and a
dimensional drawing? Knowing that a part will be available when I'm
ready to
actually mount the engine is one of the factors a builder has to consider.
Regards,
Chad
First let me be explicit and say that I don't think the Dynafocal mount is
the best mount in the world for a 13B or 20B engine. If you are BUILDING A
PLANE you would be better off using the bell housing that Butch and George
are working on along with a motor mount like what Jerry builds. Those
items are closer to reality right now. On the other hand if you have a
Lycoming powered plane flying and want to convert to a 13B or 20B then a
dynafocal front cover would be real handy and I think fill a market niche.
The part I'm working on is a complete replacement front cover for the Mazda
13B, not part of the engine mount. With it assembled on the engine you
would use whatever dynafocal-1 mount that your kit manufacturer supplied.
I'm in no position to predict a price yet so I won't even try. The
original intent was to keep the kit around $500 but that is probably a pipe
dream. I don't see it going over a grand .. yet.
As for the electric water pump tease away...................P-)
Kidding.
I'm doubtful about the ability of the EWP to handle 250 hp continuous as
well. They may work fine in the Great White North. Show me 2 hours of
continuous full power doing laps around Death Valley at 500 feet off the
deck on a hot August afternoon with only an EWP and then you'll have my
attention. The mechanical engineers in my engineering office who race
roundyround cars also don't believe the EWP will pull it off at continuous
full power for time in the tanks. These are guys who size pumps for
industrial boilers for a living.
I'm going to pursue the direct connection to the water pump off the crank
snout. No fan belt. We'll see where that goes. This will require a 3rd
gen water pump.
I talked with my apparent partner/engine builder today and we are going
ahead with a prototype and at least mount it up and see where it breaks
when it's put under a simulated G load. Rev 2 will then go on an engine to
be run on a test stand. If it all still works we'll see who wants one. Me
being an engineer, it'll have specs and dimensional drawings when I'm
finished, if for no other reason, just for the exercise of making sure it's
all there. I can't predict what will happen until we get the testing
done. This certainly isn't rocket science, it wouldn't be hard to duplicate.
Mike McGee, RV-4 N996RV, O320-E2G, Hillsboro, OR
13B in gestation mode, RD-1C, EC-2
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